Global Patent Index - EP 0940823 A4

EP 0940823 A4 20010523 - OXIDE MAGNETIC MATERIAL, FERRITE PARTICLES, BONDED MAGNET, SINTERED MAGNET, METHOD OF MANUFACTURING THE SAME, AND MAGNETIC RECORDING MEDIUM

Title (en)

OXIDE MAGNETIC MATERIAL, FERRITE PARTICLES, BONDED MAGNET, SINTERED MAGNET, METHOD OF MANUFACTURING THE SAME, AND MAGNETIC RECORDING MEDIUM

Title (de)

MAGNETISCHES OXID-MATERIAL, FERRITTEILCHEN, VERBUNDMAGNET, SINTERMAGNET, HERSTELLUNSSVERFAHREN DESSELBEN UND MAGNETISCHER AUFZEICHNUNGSTRÄGER

Title (fr)

CORPS D'OXYDE MAGNETIQUE, PARTICULES DE FERRITE, AIMANT AGGLOMERE, AIMANT FRITTE, PROCEDE DE FABRICATION DE CES MATERIAUX, ET SUPPORT D'ENREGISTREMENT MAGNETIQUE

Publication

EP 0940823 A4 20010523 (EN)

Application

EP 98943070 A 19980921

Priority

  • JP 9804242 W 19980921
  • JP 27392897 A 19970919
  • JP 20443398 A 19980703

Abstract (en)

[origin: WO9916086A1] Ferrite particles, a bonded magnet, a sintered magnet and a magnetic recording medium which are obtained from an oxide magnetic material having hexagonal crystalline structure-carrying ferrite as a main phase and containing Ca, R, Fe and M, wherein (M) is one or not less than two kinds of elements selected from Co, Ni and Zn, and (R) comprises at least one kind of element selected from rare earth elements (including Y) and Bi and necessarily includes La, whereby hexagonal ferrite having high saturation magnetization and high magnetic anisotropy, a ferrite magnet having such a high residial magnetic flux density and such a high coercive force that could not be attained in a conventional hexagonal ferrite magnet, and a ferrite magnet having a high residual magnetic flux density, a high coercive force, excellent temperature characteristics of the coercive force and little decrease in the coercive force, especially, in a low temperature region are attained. A ferrite magnet having a high residual magnetic flux density and a high coercive force and produced by using comparatively coarse ferrite particles of a grain size of over 1 mu m and a magnetic recording medium having a high residual magnetic flux density and a thermal stability are also attained.

IPC 1-7

H01F 1/11; C04B 35/26; G11B 5/706

IPC 8 full level

C04B 35/26 (2006.01); G11B 5/64 (2006.01); G11B 5/706 (2006.01); H01F 1/10 (2006.01); H01F 1/11 (2006.01); H01F 1/113 (2006.01)

CPC (source: EP US)

C04B 35/2633 (2013.01 - EP US); C04B 35/2641 (2013.01 - EP US); G11B 5/658 (2021.05 - EP US); G11B 5/70678 (2013.01 - EP US); H01F 1/10 (2013.01 - EP US); H01F 1/11 (2013.01 - EP US); H01F 1/113 (2013.01 - EP US)

Citation (search report)

  • [X] EP 0758786 A1 19970219 - TDK CORP [JP]
  • [X] US 5055322 A 19911008 - YAMAMOTO HARUHISA [JP]
  • [X] EP 0592922 A2 19940420 - KONISHIROKU PHOTO IND [JP]
  • [X] US 3114714 A 19631217 - BERNARD BRAUN POUL, et al
  • [X] US 4820433 A 19890411 - YAMAMOTO HARUHISA [JP]
  • [X] PATENT ABSTRACTS OF JAPAN vol. 009, no. 199 (P - 380) 16 August 1985 (1985-08-16)
  • [X] PATENT ABSTRACTS OF JAPAN vol. 013, no. 078 (E - 718) 22 February 1989 (1989-02-22)
  • [X] PATENT ABSTRACTS OF JAPAN vol. 013, no. 078 (E - 718) 22 February 1989 (1989-02-22)
  • [X] PATENT ABSTRACTS OF JAPAN vol. 013, no. 078 (E - 718) 22 February 1989 (1989-02-22)
  • [X] PATENT ABSTRACTS OF JAPAN vol. 013, no. 078 (E - 718) 22 February 1989 (1989-02-22)
  • See references of WO 9916086A1

Designated contracting state (EPC)

DE FR GB NL

DOCDB simple family (publication)

WO 9916086 A1 19990401; DE 69839208 D1 20080417; DE 69839208 T2 20090312; EP 0940823 A1 19990908; EP 0940823 A4 20010523; EP 0940823 B1 20080305; US 6402980 B1 20020611

DOCDB simple family (application)

JP 9804242 W 19980921; DE 69839208 T 19980921; EP 98943070 A 19980921; US 31462899 A 19990519